1. Field of the invention
The present invention relates to a treatment device for an endoscope used after being inserted into a channel for operation of an endoscope apparatus.
2. Description of Related Art
In the related art, a treatment device for an endoscope including a needle knife (treatment section), which is endoscopically inserted into a body cavity, and applies a high-frequency current to the needle knife so as to excise a membrane or the like, is known (for example, refer to JP-UM-A-61-191012).
Such a treatment device for an endoscope is configured such that a treatment section, such as the needle knife that performs a treatment on an affected part, is attached to a distal end of an operating wire inserted through an insulating sheath inserted into a channel of an endoscope. This treatment section is allowed to protrude or retract from the distal end of the sheath by operating the operating section to which a proximal end of the operating wire is fixed.
In the treatment device for an endoscope, the protruding length of the treatment section from the distal end of the sheath is generally short, and adjustment of the protruding length is not easy. Additionally, since the endoscope is inserted into a body cavity while being intricately bent, in a treatment device for an endoscope inserted into the endoscope, the operating amount of the operating section and the protruding or retracting amount of a distal end member do not correspond to 1 to 1 in many cases. For this reason, in the present situation, it is possible to precisely adjust the protruding length of the treatment section only in two states: when the treatment section is fully protruded from the sheath and when the treatment section is accommodated within the sheath.
In order to improve this problem, an incision device for an endoscope that provides a locking portion with a larger diameter than the internal diameter of a sheath in an electrode or operating section located within the sheath, thereby applying resistance to the advancing or retreating of the treatment section and allowing for fine adjustment of the protruding length is proposed (for example, refer to JP-A-No. 2004-544).